Product Information Cam and lifter kit for Big Block Chevy engines; CL-Kit includes cam, lifters, assembly lube, instructions and decals; Hydraulic - Mutha' Thumpr: High performance street/strip, needs 9:1 compression, 2500+ stall, intake, gears and headers, rough idle.; 287/304 Advertised Duration, 235/249 Duration .050", .510"/.495" Lift, 107 Lobe Separation; Valve spring upgrade required
